Self-adhesive connecting device

ABSTRACT

A device for providing a sealed liquid connection with the interior of a liquid container of a flexible sheet material, a point (8) being made to penetrate the wall (11) of the container to achieve a connection for supplying or withdrawal of liquid. According to the invention, the device is provided with a pressure sensitive adhesive (5) on a surface (4) which is intended to be applied to the container wall (11), the adhesive adhering to the container wall (11) and being arranged so that the area adhering to the container wall (11) surrounds the area where the point (8) penetrates the container wall (11). The device is intended to be applied to the container after manufacture and filling of the container and before liquid is to be added or withdrawn.

This invention relates to a device for providing a sealed liquidconnection with the interior of a liquid container made of a flexiblesheet material.

Packages of flexible sheet materials for liquids of various types havebeen widely used and have a number of advantages. Among various fieldsof use, packages for foodstuffs and various pharmacological preparationscan be mentioned as examples, and among the many advantages it can bementioned for example, that the packages are light, durable and can beproduced in large numbers at a low price. Moreover, it is possible toproduce and also to fill the packages under sterile conditions so thatthe sterility of the contents is assured. By a selection of suitableheat-resistant materials, the packages can also be heat sterilized withtheir contents.

One disadvantage of packages of flexible foil materials has been that ithas often been difficult to make a connection to the package for drawingoff its contents or adding a material to its contents. As the wallmaterial of the package is flexible and without any great rigidity, itcan be difficult to obtain a liquid-tight and leakproof connection. Thisproblem will be still greater when at the same time the contents of thepackages are to be kept sterile during and after tapping or at additionof material to the package. Soft packages of plastic foil have forexample been widely used for solutions intended for intravenous infusionto a patient, and also for blood for transfusions. It goes withoutsaying that an imperfect sterility of the package contents may havefatal consequences in such cases.

A connection to the interior of the container for supplying or drawingoff liquid is mostly obtained in such a way that a point is made topenetrate the container wall so that a connection is obtained. In mostcases, the point is hollow and can, for example, be the needle of ahypodermic syringe or of an infusion aggregate. Liquid is then drawn offor added through the channel in the needle, at which process severalproblems may occur. Such a problem is obtaining a safe seal where theneedle penetrates the container wall. Another problem is obtaining aseal when the needle has been withdrawn after completed addition ofliquid to the package, the packages mostly being made of a sheetmaterial that has inferior self-sealing properties. This means that thesheet material is not sufficiently elastic to contract so that the holeis closed and sealing is obtained after withdrawal of the needle, butthe resulting hole is still open so that leakage and bacterialcontamination occur. Certain sheet materials, especially those based onrubber, have good self-sealing properties, but they are less suitablefor the production of packages as they have unsuitable mechanical andoptical properties, are difficult to heat-seal and are also difficult tosterilize.

There are also liquid packages of flexible sheet materials which alreadyin their manufacture have been provided with passages of various typesfor supplying or drawing off liquid. Bag-shaped packages for infusionsolutions can for example be provided with two passages, one having arubber membrane for addition of liquid and the other being tubular forconnection to an infusion aggregate for administration of the infusionsolution to a patient. However, also such passages have disadvantages.Thus, the manufacture and handling of the packages will be much moretroublesome and expensive than in the manufacture of simple "cushionpackages". Besides, it may occur that several additions to the liquid inthe package must be carried out before its use, and consequently therubber membrane in the passage for additions must be penetrated with ahollow needle a number of times. This considerably increases the risk ofrubber particles being released from the membrane and getting out intothe solution. Moreover, the fixed passages will make it more difficultto arrange an outer protective bag around the package, which is oftenrequired to protect the package contents against light and penetratinggases before use. Finally, the pre-formed passages constitute potentialplaces of leakage and are weak points in an otherwise sealed and durablepackage.

The disadvantages indicated above are eliminated by this invention.According to the invention there is provided a device for achieving asealed liquid connection to the interior of a liquid container of aflexible sheet material, a point being made to penetrate the containerwall to provide a liquid connection for the addition or withdrawal ofliquid. According to the invention, the device is provided with apressure sensitive adhesive or binder on a surface which is intended tobe applied to the container wall, said adhesive adhering to thecontainer wall and being arranged such that the area intended to adhereto the container wall will surround the place where the point isintended to penetrate the container wall. The device of the invention isto be attached to the container after it has been filled, and beforeliquid is to be added or withdrawn.

The device of the invention can be embodied in a number of ways. In itseasiest embodiment, the device consists quite simply of a sheet of amaterial with self-sealing properties, e.g. a rubber membrane, which isprovided on one side with a layer of a pressure sensitive adhesive. Apiece of the sheet of a suitable size is applied to the container walland is attached to it by means of the adhesive on the place where thepoint is to be inserted through the container wall. The point of, forexample, a hypodermic syringe which has been filled with the liquid tobe added is thereafter inserted through the sheet and the wall so that aliquid connection to the interior of the container is obtained, afterwhich the liquid can be injected. Inversely, it is of course alsopossible to use an empty syringe and to draw out a desired amount ofliquid in the package. In both cases, the inserted point will be tightlysurrounded by the sheet due to the self-sealing properties of thelatter, and after withdrawal of the point, the hole in the sheet willcontract so that the package is sealed again. If several additions orwithdrawals are to be made, a new sheet is used in each case, so thatthe risk is reduced that particles of the sheet material will beintroduced into the package. By leaving the sheet on the package afteraddition or withdrawal, the package will also be marked so that it isclearly apparent which measures have been taken. In this way the risk isthus reduced that the same addition or withdrawal is carried out moretimes than intended, and this gives a greater security. The piece ofsheet applied can also be made such that the pressure sensitive adhesiveis only applied along a peripheral area, while the area in the middlewhere the point is inserted is free of adhesive. This reduces the riskof the package contents getting into contact with the adhesive.

Additional embodiments of the invention are illustrated in theaccompanying drawings. In the drawings,

FIGS. 1, 2, 3 show one embodiment, in which the self-adhering foil isconnected with a chamber for collecting and portioning of a liquid andwith a point of penetrating the container wall.

FIGS. 4, 5, 6 show a similar embodiment provided with a chamber, whereinthe arrangement of the point penetrating the container wall isdifferent.

FIGS. 7, 8, 9 show a simpler device for drawing off liquid from acontainer of a sheet material.

FIG. 10 shows connection means for a syringe point to a package forliquids.

FIG. 11 shows the device of the invention in its simplest embodiment,consisting only of a piece of sheet provided with adhesive.

FIGS. 1-3 are schematic sectional views of a connection device accordingto the invention to a liquid container of a plastic foil material. FIG.1 shows how the connection means is formed as a chamber 1 for collectingand dosing liquid. The chamber is for example made as a drop chamber forinfusion. The chamber is provided with a conical connection piece 2which is connected to a cylindrical portion 3 which is flanged out to aportion 4 intended to be attached to the container wall. For this theflanged portion 4 is provided with a layer 5 of a pressure sensitiveadhesive or binder. Before use, this layer can in a known mannerprotected by a foil 6, which is provided with a release agent so that itcan easily be removed from the layer 5.

At the rear wall 7 of the chamber 1 a point 8 for penetration of thecontainer wall is attached. The point is surrounded by a tube 9, whichprevents the point 8 from being exposed before the package wall is to bepenetrated. The point 8 does not completely fill the tube 9 but allowsflow of liquid through the tube. This can be effected in such a way thatthe point is provided with longitudinal grooves or that it is madehollow in some suitable way. The tube 9 can be provided with a device 10for drop formation, especially when the chamber is intended to serve asa drop chamber for infusion or transfusion. The detailed embodiment ofthe drop forming means 10 can be determined by one skilled in the art.

FIG. 2 shows how the device has been applied to the wall 11 of acontainer of a plastic sheet material and how the point 8 and the tube 9have penetrated the container wall. The flanged portion 4 is attached tothe container wall 11 by means of the adhesive layer 8, after which therear wall 7 of the chamber 1 with the point 8 is pushed forwards againstthe container wall 1, as shown by the arrow. This is possible becausethe chamber 1 is made of a stiff but still elastic plastic material.This applies especially to the conical portion 2, which must be able tobe turned inside out, as is apparent from FIG. 2, and then to springback, as shown in FIG. 3. When the rear wall 7 is pressed forwards, thepoint 8 attached to the wall will also be pressed forwards through thetube 9 so that the front end of the point is exposed and can penetratethe container wall 11. The tube will then be brought along by a shoulder12 on the point 8 so that it will also penetrate the hole made by thepoint in the container wall. Liquid can now flow out through the tube 9.

FIG. 3 shows the device after releasing the pressure against the rearwall 7 of the chamber. The conical portion 2 has then sprung back andthe point 8 has been drawn back through the tube 9. However, the tube isretained in the hole in the container wall 11 by friction and liquid canflow through the tube and channels in the point (not shown) to the dropforming means 10. The liquid can thereafter be led off through theconnection 13, which can be made in a conventional manner.

By the arrangement of the tube 9 around the point 8, the advantage isobtained that the point cannot penetrate the container wall in advance,as its front end is not exposed before the rear chamber wall 7 ispressed forwards. Moreover, there is no risk that the point afterpenetration of the container 1 will also damage the opposite wall in thecontainer as the point is retracted when the pressure on the rear wallof the chamber is released. However, as the tube 9 remains in the holein the container wall, a constant liquid connection is secured.

The interior of the chamber 1 can be sterilized in or after itsmanufacture and is then protected by the applied foil 6. The part of thecontainer wall where the connection means is to be applied is sterilizedimmediately before being applied, such as by washing with alcohol. Thus,in this way a completely sterile connection to the liquid container canbe obtained, as the interior of the chamber will not come into contactwith the exterior environment at the penetration of the container walland the withdrawal of liquid.

FIGS. 4, 5 and 6 show another embodiment of the connection chamber shownin FIGS. 1, 2, 3, like parts having the same reference numerals. Herethe tube 9 is attached coaxially to a snap mechanism, e.g., a conicalportion 14 of an elastic material, the peripheral portion of which isattached to the connection between the conical portion 2 and thecylindrical portion 3 of the chamber 1. Before use, the narrow portionof the cone is directed backwards towards the rear wall 7 of thechamber, as shown in FIG. 4.

When the rear chamber wall 7 is pressed forwards as is illustrated bythe arrow in FIG. 5, the conical portion 2 will first be turned insideout and the point 8 will penetrate the container wall in the same way asindicated in connection with FIG. 2. At an additional pressure forwardsthe shoulder 12 on the point 8 will press the tube 9 forwards and asthis is attached to the conical portion 14 this portion will flip overso that its narrow end is now pointing forwards and, thus retains thetube 9 in a forward position.

In FIG. 6 it is shown how pressure against the rear chamber wall 7 isreleased so that the point has been retracted due to the conical portion2 resuming its original form. However, the conical portion 14 willretain its new shape, and will therefore hold the tube 9 in the hole ofthe container wall 1 even if the frictional force is not sufficient toensure this.

Through this embodiment, a completely sterile connection to a liquidcontainer of a sheet material can also be obtained.

FIGS. 7, 8 and 9 show a simpler construction to obtain a liquidconnection to a liquid container of a sheet material. According to FIG.7, the device simply consists of a cup-shaped chamber portion 15, whichis provided with an outwardly flanged portion 16 intended to be attachedto the container wall by means of a pressure sensitive adhesive 17.Before being applied, the adhesive is protected in a conventional mannerby a foil 18, which is provided with a release agent. In the cup-shapedportion 15 a hollow point 19 is placed allowing connection with theinterior of the chamber.

FIG. 8 shows how the chamber portion is attached to a container wall 20,after which pressure is applied in the direction of the point 19 so thatthe cup-shaped chamber portion 15 is buckled inwards and the point 19will penetrate the container wall. When the pressure is released, thechamber portion 15 will spring back and bring along the point 19, asshown in FIG. 9. In this way a tight liquid connection with the interiorof the container is obtained in a simple way.

FIG. 10 shows another embodiment of the connection means according tothe invention. A sheet 21, which is intended to be attached to acontainer wall by means of a pressure sensitive adhesive, is hereprovided with a casing 22, which is tightly connected to a tube 23. Thetube 23 is made of a flexible material such as rubber or plastic and canalso be formed as a bellows. At its other end, the tube is tightlyconnected to a holder 24 for a hollow syringe needle 25. The syringeneedle 25 is surrounded by a tube 26, which is slideably arranged on thesyringe needle and is provided with an arresting shoulder 27. The holder24 of the syringe needle 25 is in its turn connected to connection means28 of a conventional type for a liquid conduit 29.

At connection to a liquid container of a sheet material, the pressuresensitive adhesive surface of the sheet 21 is first applied to thecontainer wall and attached to it. Before use, the surface with theadhesive and the interior of the tube 23 are preferably protectedagainst contamination by means of a foil provided with a releasing agent(not shown) in the same way as indicated previously. After applying thesheet 21 to the container wall, the syringe needle 25 is pressed againstthe container wall so that the wall is penetrated. As the length of thetube 26 is adapted such that its rear end rests against the holder 24 ofthe syringe needle 25 when this has just been made free, the tube 26will also be inserted into the hole made in the container wall. Theshoulder 27 will then prevent the tube 26 from being inserted too far.The introduction of the syringe point 25 is made possible as the tube 23is made of an easily flexible material such as rubber or plastic and ina preferred embodiment the tube is even formed as a bellows so that itcan be easily compressed. However, the tube 23 should have a sufficientelasticity to revert to its original form when the pressure forwardsonto the syringe needle is released. At this release of pressure, thesyringe needle will be drawn back through the hole in the container wallwhile the tube 26 will remain in the hole by the friction so that thehole is kept open and a liquid connection is assured. As the syringepoint is drawn back immediately after penetration of the container wall,there is no risk that it will damage the opposite wall of the container.This risk is otherwise great when the container has been emptied to someextent and has started to collapse due to its softness.

After the penetration of the container wall and the removal of thesyringe needle 25 liquid can flow from the container out through thetube 27, the syringe needle 25, the connection means 28 and the liquidline 29. All these parts can be maintained sterile before use and theconnection to the liquid container can also take place under sterileconditions so that complete safety is obtained, such as at anintravenous infusion or at a blood transfusion. Of course there isnothing preventing use of the device for addition of material understerile conditions.

FIG. 11 shows the simplest embodiment of the connection device accordingto the invention. Here a sheet 30 of a material with self-adhesiveproperties is attached to the container wall 32 by means of a layer 31of a pressure sensitive adhesive. For the sake of clearness, thethicknesses of the sheet 30, the adhesive layer 31 and the containerwall 32 are shown exaggerated. A hollow syringe needle is pushed throughthe sheet 30 and the container wall 32, and the contents of the liquidpackage can be drawn off through this needle or be provided withadditional material. After accomplished withdrawal or addition ofmaterial, the syringe needle is withdrawn, whereby the hole in the sheet30 is constructed by the self-sealing and elastic properties of thesheet so that a seal is obtained. On the other hand, the container wall32 is mostly made of a less elastic material, and therefore the hole init will not be contracted to sealing.

It is also apparent from FIG. 11 that the adhesive 31 need not beapplied over the whole surface of the sheet 30 but only in an annulararea along the periphery of the sheet. In this way the possibility of acontact between the contents of package and the adhesive is reduced.

A sterile connection can also be achieved by the embodiment shown inFIG. 11. The area of the package wall where the sheet is to be appliedis first washed with a bactericide, such as alcohol, and the sheet canbe kept under sterile conditions before being applied. Before applyingthe surface is protected with a protective foil treated with a releaseagent.

The embodiments shown above have primarily been concerned withconnection to containers of a flexible sheet material which are alwaysintended to contain a liquid. However, it is to be noted that theinvention is not merely restricted to this. Thus, preparations forenteral diet compositions intended for introduction through a tube arepacked sterilely in powder form in bags of a plastic sheet material.Before administration water is to be added to the powder and optionallyalso other liquids to give a liquid preparation for administration. Thissupply of liquid to the sterilely packed powder can be effectedsterilely by connection means according to the invention, the packagethus not containing any liquid initially. The withdrawal of the finishedpreparation for administration can also take place by a device accordingto the invention which can be the same as the device for the liquidsupply.

Furthermore, it should be noted that the invention is not restrictedmerely to connection and withdrawing devices for use in the medicalfield, where great demands are made on sterility. For example, a simpledevice of the type shown in FIGS. 7-9 and which can be made cheaply canbe used to provide a liquid connection to various bag-shaped consumerpackages and large packages for various foodstuffs and otherpreparations such as milk and juice, and also for packages for suchmaterials as motor oil, etc. Also here the packages can be made of suchmaterials as plastic sheet or paper coated with plastic. In eachspecific case, the advantages of the invention are obtained, i.e. asimple liquid-tight connection without leakage. The liquid packageitself need not be manufactured with finished and expensive connectionmeans from the beginning.

For the manufacture of connection devices according to the invention,materials are selected which are well-known to one skilled in the art.Here various rubber and plastic materials are primarily used, and in thecases when the materials are to have special properties such asself-sealing properties, elasticity, flexibility etc, such materials canbe easily selected by one skilled in the art on the basis of knownmaterial specifications. In the primarily considered uses, viz. in themedical and surgical field, it is of importance that the used materialscan be sterilized easily and safely, such as by heat, ionizing radiationor chemical means. Among suitable plastic materials can be mentionedpolyolefins such as polyethylene and polypropylene, halogenatedpolyolefins, such as polyvinyl chloride and fluorine plastics,polyamides such as various types of nylon, and polyesters such aspolyethylene terephthalate. As rubber materials can be used varioustypes of natural and synthetic rubber. The materials used can alsocontain various auxiliary substances such as fillers and plasticizers,but care must be taken so that the agent used will not have anydeleterious influence on the package contents with which they come intocontact.

The pressure sensitive adhesives used are also of importance. Mostly itis not intended to remove the contact-adhesive sheet from the containerbefore it has been emptied, and therefore a connection which is aspermanent and strong as possible is desired. Furthermore, an adhesiveshould be selected which has no detrimental effect on the packagecontents if they get in contact with each other. The tackiness of theadhesive is also decided by the types of material which are to bejoined. Considering these and other parameters, an expert can chooseamong a great number of known compositions for pressure sensitiveadhesives and can also select a suitable release agent for treatment ofprotective foils for the adhesive.

By the present invention, a device for obtaining a liquid-tightconnection to a liquid package of a sheet material is provided, whereinit is secured that liquid can be supplied or drawn off without any riskof waste or contamination of the package contents. In this way, theliquid package can be made simpler and at a lower cost.

It is to be noted that the embodiments of the invention shown are onlyexamples and are not intended to restrict the invention. The inventioncan also exist in other modifications and embodiments within the scopeof the claims.

We claim:
 1. A device for providing a sealed liquid connection to theinterior of a liquid container with walls of a flexible sheet material,the device including a retractable point for penetrating a wall of thecontainer to supply or draw off liquid; a pressure sensitive adhesive ona surface of the device which is adapted to be applied to the containerwall after the container has been filled, the adhesive being arrangedsuch that the area of the device which will adhere to the container wallby means of the adhesive will completely surround the location where thepoint will penetrate the container wall; and a tube surrounding thepoint and coupled to the point in a manner which constrains the tube formovement with the point through the container wall when the point ismoved in a direction to penetrate the container wall and allows the tubeto continue to protrude through the hole made in the wall after thepoint is retracted.
 2. The device of claim 1, wherein the tubesurrounding the point is attached to a snap mechanism, which snapmechanism flips over when the point and the tube are inserted to aposition which prevents withdrawal of the tube as the point is beingretracted.